let A be Euclidean preIfWhileAlgebra; :: thesis: for X being non empty countable set
for s being Element of Funcs X,INT
for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P holds
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)

let X be non empty countable set ; :: thesis: for s being Element of Funcs X,INT
for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P holds
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)

let s be Element of Funcs X,INT ; :: thesis: for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P holds
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)

let b be Element of X; :: thesis: for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P holds
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)

let g be Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0 ; :: thesis: for P being set
for I being Element of A
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P holds
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)

let P be set ; :: thesis: for I being Element of A
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P holds
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)

let I be Element of A; :: thesis: for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P holds
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)

let i, n be Variable of g; :: thesis: ( ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) & s in P implies g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n) )

given d being Function such that D0: ( d . b = 0 & d . n = 1 & d . i = 2 ) ; :: thesis: ( ex s being Element of Funcs X,INT st
( s in P & not ( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) ) or not s in P or g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n) )

D1: ( b <> i & b <> n & i <> n ) by D0;
assume that
00: for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in P & g . s,(i leq n) in P & g . s,(i += 1) in P ) and
A0: s in P ; :: thesis: g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n)
set h = g;
set S = Funcs X,INT ;
set T = (Funcs X,INT ) \ b,0 ;
set C = i leq n;
set J = i += 1;
reconsider s1 = g . s,(i leq n) as Element of Funcs X,INT ;
defpred S1[ Element of Funcs X,INT ] means $1 in P;
defpred S2[ Element of Funcs X,INT ] means $1 . i <= $1 . n;
deffunc H1( Element of Funcs X,INT ) -> Element of NAT = In ((($1 . n) + 1) - ($1 . i)),NAT ;
AA: S1[s1] by A0, 00;
( ( s . i > s . n implies s1 . b = 0 ) & ( s . i > s . n or s . i <= s . n ) & s1 . i = s . i & s1 . n = s . n & ( s . i <= s . n implies s1 . b = 1 ) ) by D0, Th114;
then AB: ( s1 in (Funcs X,INT ) \ b,0 iff S2[s1] ) by LemTS;
C: for s being Element of Funcs X,INT st S1[s] & s in (Funcs X,INT ) \ b,0 & S2[s] holds
( S1[g . s,((I \; (i += 1)) \; (i leq n))] & ( S2[g . s,((I \; (i += 1)) \; (i leq n))] implies g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 ) & ( g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 implies S2[g . s,((I \; (i += 1)) \; (i leq n))] ) & H1(g . s,((I \; (i += 1)) \; (i leq n))) < H1(s) )
proof
let s be Element of Funcs X,INT ; :: thesis: ( S1[s] & s in (Funcs X,INT ) \ b,0 & S2[s] implies ( S1[g . s,((I \; (i += 1)) \; (i leq n))] & ( S2[g . s,((I \; (i += 1)) \; (i leq n))] implies g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 ) & ( g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 implies S2[g . s,((I \; (i += 1)) \; (i leq n))] ) & H1(g . s,((I \; (i += 1)) \; (i leq n))) < H1(s) ) )
assume 01: ( S1[s] & s in (Funcs X,INT ) \ b,0 & S2[s] ) ; :: thesis: ( S1[g . s,((I \; (i += 1)) \; (i leq n))] & ( S2[g . s,((I \; (i += 1)) \; (i leq n))] implies g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 ) & ( g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 implies S2[g . s,((I \; (i += 1)) \; (i leq n))] ) & H1(g . s,((I \; (i += 1)) \; (i leq n))) < H1(s) )
then reconsider ni = (s . n) - (s . i) as Element of NAT by INT_1:16, XREAL_1:50;
set s1 = g . s,I;
set q = g . s,(I \; (i += 1));
set q1 = g . (g . s,(I \; (i += 1))),(i leq n);
03: ( ( (g . s,(I \; (i += 1))) . i > (g . s,(I \; (i += 1))) . n implies (g . (g . s,(I \; (i += 1))),(i leq n)) . b = 0 ) & ( (g . s,(I \; (i += 1))) . i > (g . s,(I \; (i += 1))) . n or (g . s,(I \; (i += 1))) . i <= (g . s,(I \; (i += 1))) . n ) & (g . (g . s,(I \; (i += 1))),(i leq n)) . i = (g . s,(I \; (i += 1))) . i & (g . (g . s,(I \; (i += 1))),(i leq n)) . n = (g . s,(I \; (i += 1))) . n & ( (g . s,(I \; (i += 1))) . i <= (g . s,(I \; (i += 1))) . n implies (g . (g . s,(I \; (i += 1))),(i leq n)) . b = 1 ) ) by D0, Th114;
02: ( g . s,(I \; (i += 1)) = g . (g . s,I),(i += 1) & g . (g . s,(I \; (i += 1))),(i leq n) = g . s,((I \; (i += 1)) \; (i leq n)) ) by AOFA_000:def 29;
S1[g . s,I] by 01, 00;
then S1[g . s,(I \; (i += 1))] by 00, 02;
hence S1[g . s,((I \; (i += 1)) \; (i leq n))] by 00, 02; :: thesis: ( ( S2[g . s,((I \; (i += 1)) \; (i leq n))] implies g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 ) & ( g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 implies S2[g . s,((I \; (i += 1)) \; (i leq n))] ) & H1(g . s,((I \; (i += 1)) \; (i leq n))) < H1(s) )
thus ( S2[g . s,((I \; (i += 1)) \; (i leq n))] iff g . s,((I \; (i += 1)) \; (i leq n)) in (Funcs X,INT ) \ b,0 ) by 02, 03, LemTS; :: thesis: H1(g . s,((I \; (i += 1)) \; (i leq n))) < H1(s)
( (g . s,I) . i = s . i & (g . s,I) . n = s . n ) by 01, 00;
then ( (g . s,(I \; (i += 1))) . i = (s . i) + 1 & (g . s,(I \; (i += 1))) . n = s . n ) by 02, D1, Th012;
then ( (g . (g . s,(I \; (i += 1))),(i leq n)) . i = (s . i) + 1 & (g . (g . s,(I \; (i += 1))),(i leq n)) . n = s . n ) by D0, Th114;
then ( H1(g . (g . s,(I \; (i += 1))),(i leq n)) = ni & H1(s) = ni + 1 ) by FUNCT_7:def 1;
hence H1(g . s,((I \; (i += 1)) \; (i leq n))) < H1(s) by 02, NAT_1:13; :: thesis: verum
end;
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),s1 from AOFA_000:sch 4(AA, AB, C);
hence g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . s,(i leq n) ; :: thesis: verum